landlock: Report the effective signal number

The signal-scope denial callback identifies its target but not the
effective signal. This loses permission-probe signal zero and makes the
file-owner hook's zero sentinel ambiguous.

Append an int signal argument to the typed-BPF callback. Preserve sig,
including zero, in hook_task_kill(). In hook_file_send_sigiotask(),
translate signum zero to SIGIO at the producer, where its meaning is
known.

Carry the effective signal and target domain ID in a private,
stack-backed context consumed synchronously. This requires no allocation
or task reference in the interrupt-capable file-owner path. Gate this
context and the remaining scope-only domain IDs with CONFIG_TRACEPOINTS.

Keep the tracefs record and audit output unchanged.

Cc: Günther Noack <gnoack@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Fixes: bb91730f16c0 ("landlock: Add tracepoints for ptrace and scope denials")
Link: https://patch.msgid.link/20260918185036.608651-7-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>

0 files changed, 0 insertions, 0 deletions